The present invention relates to disklike recording media, such as CD (i.e., compact disk) and DVD (i.e., digital video disk or digital versatile disk), which are suitable for mass production and wide-areal distribution. More specifically, the present invention relates to an anti-forgery system, and related detecting apparatuses installable in the distribution channel or in a center office equipped with a host computer. Moreover, the present invention relates to a manufacturing method and apparatus for recording the information for a true-false judgement on the surfaces of the disk.
The conventional CD is preferably used for recording the audio information or program. The conventional VHD or LD is preferably used for recording video or image information. However, a recently developed DVD has a very large recording capacity which is approximately 5 to 7 times the recording capacity of the above-described conventional disks. Thus, the CD, VHD and LD will be replaced by DVD-Audio and DVD-Video.
In other words, the high-density recording media can provide an added value due to their large recording capacity. On the other hand, the industrial damage and monetary loss will be very large if they are subjected to the forgery.
An object of the present invention is to provide an anti-forgery system capable of accurately detecting forged products of the disklike recoding media at an earlier stage of the circulation of the forged products.
In order to accomplish the above and other related objects, one aspect of the present invention provides a recording medium comprising first information selected from a plurality of information patterns for a true-false judgement, and second information selected from another plurality of information patterns for the true-false judgement.
Preferably, the recording medium has a disklike body with a first surface on which the first information is recorded and a second surface on which the second information is recorded. In this case, the first information may be a pit or groove pattern formed on the first surface. A registered combination pattern of an enciphered format may be recorded on a specific area of a disk surface other than the first information and the second information. The first information and the second information are combined randomly.
Another aspect of the pre sent invention provides a system for detecting forged products of recording media. This system comprises a reading means for reading first information and second information from an inspected recording medium, a memory means for storing a plurality of registered combination patterns for a true-false judgement, and a true-false judging means for identifying the inspected recording medium as a forged product when no coincidence is found between a readout combination of the first and second information and the registered combination patterns.
Preferably, the true-false judging means is for further performing a statistic analysis when any coincidence is found between the readout combination and the registered combination patterns, thereby identifying the inspected recording medium as a forged product based on the result of the statistic analysis.
Preferably, in the statistic analysis, the true-false judging means is for detecting a combination pattern of the first and second information recorded on the forged product with reference to a standard deviation or a time differential value of the standard deviation.
Another aspect of the present invention provides an apparatus for detecting forged products of recording media. This apparatus comprises a reading means for reading first information and second information from an inspected recording medium, a transmitting means for transmitting a readout combination of the first and second information to a true-false judging apparatus, a receiving means for receiving a true-false judgement result from the true-false judging apparatus, and an output means for outputting the true-false judgement result.
Preferably, the readout combination of the first and second information is transmitted to the true-false judging apparatus by using a communication device and related communication software. The apparatus may be a playback apparatus of the disklike recording medium.
Another aspect of the present invention provides an apparatus for detecting forged products of recording. media. This apparatus comprises a memory means for storing a plurality of registered combination patterns for a true-false judgement, a receiving means for receiving a combination of first and second information read out from an inspected recording medium, and a true-false judging means for identifying the inspected recording medium as a forged product when no coincidence is found between the readout combination of the first and second information and the registered combination patterns.
In this case, the true-false judging means is for further performing a statistic analysis when any coincidence is found between the readout combination and the registered combination patterns, so as to identify the inspected recording medium as a forged product based on the result of the statistic analysis. The true-false judging means is for detecting a combination pattern of the first and second information recorded on the forged product with reference to a standard deviation or a time differential value of this standard deviation.
Moreover, another aspect of the present invention provides a manufacturing apparatus for a disklike recording medium. This manufacturing apparatus comprises a first recording means for recording main information including first information on a first surface of the disklike recording medium, and a second recording means for recording second information on a second surface of the disklike recording medium. Each of the first and second information is selected from a plurality of information patterns for a true-false judgement.